首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   63篇
  免费   8篇
  国内免费   1篇
化学   52篇
力学   5篇
数学   1篇
物理学   14篇
  2023年   1篇
  2022年   2篇
  2021年   3篇
  2020年   1篇
  2019年   2篇
  2018年   2篇
  2017年   2篇
  2016年   3篇
  2015年   1篇
  2014年   6篇
  2013年   5篇
  2012年   8篇
  2011年   8篇
  2009年   4篇
  2008年   4篇
  2007年   6篇
  2006年   1篇
  2004年   1篇
  2002年   1篇
  2000年   1篇
  1999年   2篇
  1997年   2篇
  1996年   3篇
  1994年   1篇
  1990年   2篇
排序方式: 共有72条查询结果,搜索用时 30 毫秒
61.
EMS磁浮列车车/轨耦合系统的分岔现象研究   总被引:8,自引:0,他引:8  
通过分析EMS磁浮列车系统的Hopf分岔, 研究车轨耦合系统对应的轨道固有频率稳定范围. 采用串级控制悬浮控制器,给出控制器参数与特征频率的关系,在控制器稳定的前提下利用 数值算法计算在系统参数一定、轨道固有频率变化条件下所对应的Hopf分岔点,结合仿真方法 得出轨道固有频率的稳定范围,定性说明了系统载荷、控制器频率、二次系刚度与轨道固有 频率之间的变化关系.  相似文献   
62.
在百焦耳级XeCl准分子激光器上,开展了强紫外激光辐照LY—12铝靶和碳纤维靶的光学诊断实验。研究了靶面对激光的反射系数随入射激光功率密度的变化规律,获得了激光等离子体光谱及蒸汽羽积分图象等实验结果。  相似文献   
63.
A novel amperometric glucose biosensor based on layer‐by‐layer (LbL) electrostatic adsorption of glucose oxidase (GOx) and dendrimer‐encapsulated Pt nanoparticles (Pt‐DENs) on multiwalled carbon nanotubes (CNTs) was described. Anionic GOx was immobilized on the negatively charged CNTs surface by alternatively assembling a cationic Pt‐DENs layer and an anionic GOx layer. Transmission electron microscopy images and ζ‐potentials proved the formation of layer‐by‐layer nanostructures on carboxyl‐functionalized CNTs. LbL technique provided a favorable microenvironment to keep the bioactivity of GOx and prevent enzyme molecule leakage. The excellent electrocatalytic activity of CNTs and Pt‐DENs toward H2O2 and special three‐dimensional structure of the enzyme electrode resulted in good characteristics such as a low detection limit of 2.5 μM, a wide linear range of 5 μM–0.65 mM, a short response time (within 5 s), and high sensitivity (30.64 μA mM?1 cm?2) and stability (80% remains after 30 days).  相似文献   
64.
Since serious fire occurred frequently in recent years, fire safety of high-rise building hasattracted extensive attention. A National Basic Research Program (973 program) of China has been setup by Ministry of Science and Technology (MOST) of China in 2012 to meet the research requirementsof fire safety in high-rise buildings. This paper reviews the current state of art of research onfire dynamics of high-rise buildings, including the up-to-date progress of this project. Thefollowing three subjects on fire dynamics of high-rise buildings are addressed in this review: theejected flame and fire plumebehavior over facade out ofthe compartment window, the flame spread behavior over facade thermal insulation materials, and the buoyancy-driven smoke transportationcharacteristicsalong long vertical channels in high-rise buildings. Prospective future works are discussed andsummarized.  相似文献   
65.
镍(Ⅱ)的反相萃取柱色层新体系研究及应用   总被引:1,自引:0,他引:1  
谭龙华  谢烈文 《分析化学》1990,18(5):444-446
  相似文献   
66.
67.
Tang L  Zhu Y  Yang X  Li C 《Analytica chimica acta》2007,597(1):145-150
An enhanced amperometric biosensor based on incorporating one kind of unique nanobiocomposite as dopant within an electropolymerized polypyrrole film has been investigated. The nanobiocomposite was synthesized by self-assembling glutamate dehydrogenase (GLDH) and poly(amidoamine) dendrimer-encapsulated platinum nanoparticles (Pt-DENs) onto multiwall carbon nanotubes (CNTs). ζ-Potentials and high-resolution transmission electron microscopy (HRTEM) confirmed the uniform growth of the layer-by-layer nanostructures onto the carboxyl-functionalized CNTs. The size of Pt nanoparticles is approximately 3 nm. The (GLDH/Pt-DENs)n/CNTs/Ppy hybrid film was obtained by electropolymerization of pyrrole onto glassy carbon electrodes and characterized with scanning electron microscopy (SEM), cyclic voltammetry (CV) and other electrochemical measurements. All methods indicated that the (GLDH/Pt-DENs)n/CNTs nanobiocomposites were entrapped within the porous polypyrrole film and resulted in a hybrid film that showed a high electrocatalytic ability toward the oxidation of glutamate at a potential 0.2 V versus Ag/AgCl. The biosensor shows performance characteristics with high sensitivity (51.48 μA mM−1), rapid response (within 3 s), low detection limit (about 10 nM), low level of interference and excellent reproducibility and stability.  相似文献   
68.
This review presents a comprehensive survey of recent progress on electrochemiluminescence (ECL) detection coupled with capillary electrophoresis (CE). The fundamental theories involved in CE-ECL, e.g., the mechanism involving both coreactant-based and inhibitor-based ECL, as well as the possible analytes to be detected by CE-ECL are summarized. Different schemes for the construction of CE-ECL apparatus, including methods for preparing the working electrode, approaches for addition of ECL reagents, ways to fabricate electrical decouplers, and factors affecting ECL efficiency are reviewed. Discussion of the literature related to the application of CE-ECL from January 2005 to September 2010 is sorted by the corresponding analyte matrixes, namely, the standard solution, urine, serum and plasma, and other matrixes. Finally, possible trends for CE-ECL in the near future are discussed.  相似文献   
69.
DNA is in control: Different combinations of DNA nucleotides can control the shape and surface roughness of gold nanoparticles during their synthesis. These nanoparticles were synthesized in the presence of either homogenous oligonucleotides or mixed-base oligonucleotides using gold nanoprisms as seeds. The effect of the individual DNA bases and their combinations on shape control are shown in the figure.  相似文献   
70.
Based on the specific folic acid-folate receptor (FA-FR) interaction, macromolecular FR can bind with FA-linked DNA-small molecule chimeras, which can prevent enzymolysis by exonuclease III (Exo III), enabling a novel fluorescence biosensor for FR to be developed using quinaldine red as a G-quadruplex-binding probe.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号